CFD ‐based studies on solar chimneys in buildings with emphasis on indoor air quality and E4 assessments: A systematic review

Abstract Solar chimneys have advanced from geometric parameter analyses to nano‐enhanced hybrid systems, yet a disconnect persists between engineering performance and health‐relevant indoor air quality validation. Analysis of 62 CFD studies (2012–2025) shows 95% used air changes per hour (ACH) as an IAQ proxy, without measuring pollutant concentrations or validating against health thresholds like <1000 ppm CO 2 for cognitive performance. Only one study incorporated indoor CO 2 measurements, and none linked ventilation enhancements to occupant health outcomes. Holistic E4 assessment (energy, exergy, environmental, economic) was also fragmented; exergy analysis appeared in only 3%, life cycle assessment in 2%, and no study implemented a unified E4 framework. Despite growing hybrid system complexity, this sophistication failed to address the assumption that increased airflow inherently improves occupant health. The field's credibility as a public health intervention remains undermined by conflating ventilation quantity with air quality. A framework is proposed to address this gap, including pollutant transport modeling, dynamic CO 2 ‐based ACH targets, integrated E4 assessment, and occupant‐centered validation. Without explicit linkage between ventilation rates and health‐relevant exposure metrics, current solar chimney performance claims remain largely theoretical. The proposed framework attempts to transition these systems from engineering abstractions toward potential evidence‐based solutions for indoor environmental quality.